[sbc100]

Since #28144, every C define in struct_info.json is added to LibraryManager.library as three entries ($FOO, $FOO__const, and $FOO__internal). Adding hundreds more constants to struct_info.json (as in #28199) would otherwise incur two compile-time performance costs in compiler.mjs:

1. In --symbols-only mode we only need to discover transitive dependencies on native symbols. As JS library functions replace magic numbers with struct_info.json constants, addImplicitDeps (src/jsifier.mjs) would otherwise record every referenced constant in __deps and repeatedly traverse them in getTransitiveDeps. Skipping __const symbols in --symbols-only mode avoids this work.

2. Each struct_info.json constant adds three keys to LibraryManager.library, which is iterated over in multiple passes that call isDecorator (src/utility.mjs) on every key. Using lastIndexOf('__') and a Set lookup instead of decoratorSuffixes.some with endsWith avoids scanning all 15 decorator suffixes for every key in the library.

See: #28199

[sbc100]

I'd like to land this before #28199

[gemini-code-assist]

Code Review

This pull request optimizes dependency resolution and decorator suffix checks. In src/jsifier.mjs, a check is added to skip implicit dependencies when symbolsOnly is active and a constant variant of the dependency exists. In src/utility.mjs, the isDecorator function is optimized by converting the decoratorSuffixes array into a Set and checking the suffix using lastIndexOf instead of iterating with some. There are no review comments, and I have no feedback to provide.